[LTP] [PATCH v2] Migrating the libhugetlbfs/testcases/truncate.c test

[Cyril Hrubis]

Hi!
> +/*\
> + * [Description]
> + *
> + * Test Name: truncate
> + * Test case is used to verify the correct functionality
> + * and compatibility of the library with the "truncate" system call when
> + * operating on files residing in a mounted huge page filesystem.
> + */
> +
> +#include "hugetlb.h"
> +
> +#define RANDOM_CONSTANT	0x1234ABCD
             ^
	     THis is not used at all.

> +#define MNTPOINT "hugetlbfs/"
> +long hpage_size;
> +int fd;

These two should be static.

> +
> +
> +static void sigbus_handler(int signum LTP_ATTRIBUTE_UNUSED)
> +{
> +	tst_res(TPASS, "Test Passed");
> +	exit(0);

It's not safe to call exit(0) from a signal handler.

What should be done instead is to:

- add global static volatile int variable
- reset it before we attempt to access the truncated memory
- set it in the signal handler
- print TPASS/TFAIL based on the value of the variable in the run_test()
  function

> +}
> +
> +static void run_test(void)
> +{
> +	void *p;
> +	volatile unsigned int *q;
         ^
	I do not think that this has to be volatile.

	All in all this can be just:

	unsigned int *p;

	...

	p = SAFE_MMAP();

	...

	*p = 0;

> +	struct sigaction my_sigaction;
> +	my_sigaction.sa_handler = sigbus_handler;
> +	p = SAFE_MMAP(NULL, hpage_size, PROT_READ|PROT_WRITE, MAP_SHARED,
> +			fd, 0);
> +	if (p == MAP_FAILED)
> +		tst_res(TFAIL, "mmap failed..!!");

SAFE_MMAP() cannot fail, it does exit the test with a failure if the it
fails to map the memory.

> +	q = p;
> +	*q = 0;
> +	SAFE_SIGACTION(SIGBUS, &my_sigaction, NULL);

I guess that we can set up the handler in the setup instead.

> +	SAFE_FTRUNCATE(fd, 0);
> +	*q;
> +        tst_res(TFAIL, "Didn't SIGBUS");

And we should SAFE_UNMAP() the memory here.

Also does the test work with -i 2 ?

> +}
> +
> +
> +void setup(void)
> +{
> +	hpage_size = tst_get_hugepage_size();
> +    	fd = tst_creat_unlinked(MNTPOINT, 0);
   ^
   Wrong indentation, please make sure to run 'make check' and fix all
   the reported problems.

> +}
> +
> +void cleanup(void)
> +{
> +    	if (fd > 0)
> +	    SAFE_CLOSE(fd);
> +}
> +
> +static struct tst_test test = {
> +	.needs_root = 1,
> +	.mntpoint = MNTPOINT,
> +	.needs_hugetlbfs = 1,
> +	.needs_tmpdir = 1,
> +	.setup = setup,
> +	.cleanup = cleanup,
> +	.test_all = run_test,
> +	.hugepages = {1, TST_NEEDS},
> +};
> -- 
> 2.39.3
> 
> 
> -- 
> Mailing list info: https://lists.linux.it/listinfo/ltp

-- 
Cyril Hrubis
chrubis@suse.cz